أَوْ تَأْتِىَ بِاللَّهِ وَالْمَلَـئِكَةِ قَبِيلاً
(or you bring Allah and the angels before (us) face to face.) 17:92
قَالُواْ لَن نُّؤْمِنَ حَتَّى نُؤْتَى مِثْلَ مَآ أُوتِىَ رُسُلُ اللَّهِ
(They said: "We shall not believe until we receive the like of that which the Messengers of Allah had received.") 6:124 and,
وَقَالَ الَّذِينَ لاَ يَرْجُونَ لِقَآءَنَا لَوْلاَ أُنزِلَ عَلَيْنَا الْمَلَـئِكَةُ أَوْ نَرَى رَبَّنَا لَقَدِ اسْتَكْبَرُواْ فِى أَنفُسِهِمْ وَعَتَوْا عُتُوّاً كَبِيراً
(And those who expect not a meeting with Us said: "Why are not the angels sent down to us, or why do we not see our Lord" Indeed they think too highly of themselves, and are scornful with great pride.) 25:21 Allah said,
وَكَلَّمَهُمُ الْمَوْتَى
(and the dead had spoken unto them,) This is, to inform them of the truth of what the Messengers brought them;
وَحَشَرْنَا عَلَيْهِمْ كُلَّ شَىْءٍ قُبُلاً
(and We had gathered together all things before them,) before their eyes, as `Ali bin Abi Talhah and Al-`Awfi reported from Ibn `Abbas. This is the view of Qatadah and `Abdur-Rahman bin Zayd bin Aslam. This Ayah means, if all nations were gathered before them, one after the other, and each one testifies to the truth of what the Messengers came with,
مَّا كَانُواْ لِيُؤْمِنُواْ إِلاَّ أَن يَشَآءَ اللَّهُ
(they would not have believed, unless Allah willed,) for guidance is with Allah not with them. Certainly, Allah guides whom He wills and misguides whom He wills, and He does what He wills,
لاَ يُسْأَلُ عَمَّا يَفْعَلُ وَهُمْ يُسْـَلُونَ
(He cannot be questioned about what He does, while they will be questioned.) 21:23, This is due to His knowledge, wisdom, power, supreme authority and irresistibility. Similarly, Allah said,
إِنَّ الَّذِينَ حَقَّتْ عَلَيْهِمْ كَلِمَةُ رَبِّكَ لاَ يُؤْمِنُونَ - وَلَوْ جَآءَتْهُمْ كُلُّ ءايَةٍ حَتَّى يَرَوُاْ الْعَذَابَ الاٌّلِيمَ
(Truly, those, against whom the Word (wrath) of your Lord has been justified, will not believe. Even if every sign should come to them, until they see the painful torment.) 10:96-97
Tafsir Ibn Kathir (abridged, English).